Exhaust muffler and oxidizer



May 30, 1961 s. G. GERLACH EXHAUST MUFFLER AND OXIDIZER 2 Sheets-Sheet 1 Filed June 15, 1959 INVENTOR. & a%e7z 562' riczc Zmzz May 30, 1961 s. G. GERLACH EXHAUST MUFFLER AND OXIDIZER fi e a .8 a m "7 2 H k... a w M W 2 2M y Q e y W 8 United States Patent Ofice Patented May 30, 1961 EXHAUST MUFFLER AND OXIDIZER Stephen G. Gerlach, 723 E. Providencia St., Burbank, Calif.

Filed June 15, 1959, Ser. No. 820,162

7 Claims. (Cl. 60-30) This invention relates to improvements in combined mufilers and afterburners for the exhaust gases of internal combustion engines.

Scientific study has established that one of the principal constituents of significant air pollution in and around areas in which there is a concentration of automotive vehicles is the unburned components of the exhaust of the engines from those vehicles. Such pollution is generally known as smog. Various attempts have been made to solve the problem of reducing such air pollution and, in general, those attempted solutions or proposals have taken one of two general forms. One form is some sort of regulation of the fuel intake of the engines to the end that the fuel supplied to the engine shall as far as possible only be in such quantity as is actually consumed incident to the operation of the engine at its various speeds and condition of throttle opening in response to the load imposed on the engine.

Another approach to the problem has been along lines such as proposed in the present invention, viz., to disregard the fuel intake changes and so far as is possible insure that any unburned fuel emitted with the exhaust is oxidized before being released to the atmosphere. Such devices whether combined with the mufiler for silencing the noise of the exhaust or installed as a separate instrumentality are generally known as afterburners. So far as is known, all such attempts to produce a satisfactory afterburner have heretofore followed the general path of muffler design in that the body of the device is formed (as has been the practice in the manufacture of muifiers) from sheet metal, notwithstanding the fact that the burning of the unburned gases develops heat to such an extent that the sheet metal is in danger of being rapidly destroyed.

The present invention, therefore, proposes to depart from the conventional muffler design heretofore generally followed in the proposals for afterburners and instead proposes to construct an afterburner formed of iron or steel castings whereby greater resistance to the deleterious efiects of heat and the better retention of generated heat to assist in oxidation of unburned fuel in the exhaust gases passing therethrough is achieved.

With the foregoing objects in view, together with such additional objects and advantages as may subsequently appear, the invention resides in the parts, and in the construction, combination and arrangement of parts described, by way of example, in the following specification of a presently preferred embodiment of the invention, reference being had to the accompanying drawings which form a part of said specification and in which drawings:

Fig. 1 is a side elevational view of a combined mufiler and afterburner embodying the present invention,

Fig. 2 is a bottom plan view of the device,

Fig. 3 is an enlarged top plan view of the bottom half of the device, the view being taken on the line 33 of Fig. 1 and the securing bolts and certain of the interior elements being shown in section taken on the said line 3--3,

Fig. 4 is a transverse sectional view on the same scale as Fig. 3 taken on the lines 44 of Figs. 1 and 3,

Fig. 5 is a fragmentary medial sectional view taken on the line 5-5 of Fig. 2, the scale being the same as that of Fig. 3 and the device being in the position shown in Fig. 3,

Figs. 6 and 7 are transverse sectional views taken on the lines 66 and 77 respectively, of Fig. 5, and

'Fig. 8 is a fragmentary sectional view taken on the lines 88 of Fig. 7.

Referring to the drawings the illustrated embodiment of the invention comprises an elongated, hollow body or casing 1, preferably formed of cast iron or cast steel which is substantially square in transverse section and is formed from substantially identical upper and lower halves 2 and 3 secured together in a medial, longitudinal plane by screws 4 extending through holes along the sides of the lower half 3 and engaging mating threaded holes in the upper half 2. The halves are formed from identical castings and, as finished, for assembly are identical except for the diiferences in accommodating the securing screws 4 and a provision for the introduction of electrical conductors through the lower half as will be later referred to in detail.

At one end thereof, the housing members 2 and 3 are formed with semi-circular clearances generated about the longitudinal center line of the body, said clearances combining to form a circular entrance port 5 in which the discharge end of an exhaust pipe E extending from the exhaust manifold of the engine may be inserted and clamped by tightening the pair of screws 4, 4 on each side thereof. The port 5 terminates in an annular shoulder portion 6 limiting the distance to which the exhaust pipe may project into the port 5. At their 0pposite ends, the body halves 2 and 3 terminate in halves forming a sleeve portion 7 axially aligned with the longitudinal centerline of the body and adapted to be embraced by a discharge pipe D leading to the rear end of the vehicle. The body halves 2 and 3 are hollow and define a generally rectangular space extending from end to end of the body, the configuration of the interior of said space being shown for example in Fig. 4. Said internal space is divided by transverse Walls 8 and 8' adjacent the entrant and discharge ends respectively of the housing and by an intermediate wall 9 into a series of compartments. For convenience in description the compartments in the interior of the body formed by these partitions will be designated, starting from the exhaust entrant end as compartments A, B and a combustion chamber C and C. Additionally, the partition 9 on the side thereof facing the compartment C is provided with a vertically extending laterally thickened portion 10 which portion in the casting forming the lower half 3 is provided with a bore for an insulator 11 extending upwardly to a point near the upper face thereof, said insulator being of ceramic or equivalent heat resistant material and carrying electrical conductors as will be later described.

The meeting faces of the partitions 8, 8 and 9 adjacent the sides of the housing are provided with semicircular, mating clearance spaces which combine to form circular seats 12, 12 for conduit means for conducting exhaust gases through the device and including a pair of tubes 13, 13 disposed within the cavities and extending from open ends within the compartment A to open ends within the compartment B, the portions of the tubes extending through the compartments B and C being provided with a series of elongated perforations 14. Adjacent each end, each of the tubes is provided with a peripheral rib 15 engaging the faces of the partitions 8 and 8' which bound the 3 compartments B and C, respectively, and which thus serve to hold the tubes l3, 13 against endwise movement.

The partitions 3-4; of the upper and lower halves 2 and 3 are each provided with opposed, mating semicircular recesses disposed in the longitudinal center line of the body which combine to form a circular seat 16 for the gas entrant end of a mixing chamber component of another conduit means for the exhaust gases 17, said component having an outwardly flared entrant end 13. The component 17 is generally tubular and is provided with a shoulder portion 19 engaging the face of the partition 8 in the compartment B. The opposite end of the mixing chamber is reduced in diameter as at 2t. and is seated in a circular seat 21 formed by mating semicircular recesses formed in the mating faces of the partitions d, h and the thickened portions 1%, thereof. The shoulder formed by the juncture of the body of the mixing chamber member and the reduced diameter end 2i) thereof engages the faces of the partitions 9, 9 which lie in the compartment B and thus cooperates with the shoulder at the opposite end of the mixing chamber to hold the mixing chamber against endwise movement. As will be best seen in Fig. 7, the partition 8' is provided with a series of holes 22. extending therethrough affording communication between the compartments B and C. Mounted in the second portion 10 of the partition and also in the partition 8' in axial alignment with the mixing chamber is a tubular heating chamber component 23 of the said other conduit means for exhaust gases; said heating chamber component having a small tubular end 24 disposed in end to end relation with the small end of the mixing chamber, a diffusing screen 25 being interposed between the ends of the two chambers. The smaller portion 24 of the heating chamber 23 thence extends in an outwardly flared portion 26 to a larger straight tubular portion 27 having a peripheral bead 28 formed in the outer surface thereof adjacent the distal end. The partition 8 is formed with opposed semi-circular recesses which combine to form the circular seat for circular bead 29 on the said distal end 27 of the heating chamber and within the combustion chamber C, the distal end of the heating chamber is provided with a screen 30 through which the thus heated gas and air passes into the combustion chamber and which confines combustion to the down-stream side of said screen.

The mixing chamber 17 is provided with a series of radially extending holes '51 affording communication between the interior of said mixing chamber and the compartment B and at its distal end the mixing chamber is tapered as at 32 to communicate with the reduced diameter bore extending through the end 2t) thereof.

The side edges of the top and bottom halves 2 and 3 are provided with longitudinally extending grooves which combine to form circular channels 33 extending from the discharge end of the body to the wall at the entrant end of the body and which thence curve as at 34 into the compartment A. Mounted in these recesses are air tubes 35, 35 which project slightly beyond the distal end of the body 1 and are provided with perforations 36. The tubes thence extend in side by side relation to discharge ends 37, 37 within the mixing chamber 17 as best shown in Figs. 3 and 4.

The smaller diameter straight portion 24 of the heating chamber 23 is surrounded by a layer of mica 38 and around this insulating layer is a coil 39 of electrical resistance wire which (see Fig. 5) is connected by leads 4t) to the conductors 41 extending through the insulator ill and which are connected by wires W to a suitable source of energy.

Exhaust gas from the engine enters the device through the pipe E and portions of the exhaust go through the mix ing chamber thence through the heating chamber where it is heated by the heating element 39 and passes on through the Meker burner screen 30 at which point it is sufliciently heated to be self-igniting. Another portion of the exhaust gases enter the entrant ends of the tubes 13, 13 and goes in and out of the perforations therein within the compartments B and C, with resultant silencing of the pulsations of the gases received from the engine and eventually mixes with the gas coming through the mixing and heating chambers. At the same time air is being drawn into the mixing chamber through the tubes 35, 35 to provide oxygen for combustion purposes. Attention is directed to the simplicity of construction in that all of the separate parts contained within the body arelocated in recesses formed in different portions of the body which mate with each other and therefore, upon closing the body by bolting the two halves thereof together, the entire assembly is effected. Attention is further directed to the fact that the body is formed of castings which are identical halves and, as previously recited, are slightly differently machined to form the upper and lower halves of the body construction.

While the foregoing specification discloses a presently preferred embodiment of the invention, it will be understood that the invention is not to be deemed to be limited to the form thus shown by way of example and it will be understood that the invention includes as well all such changes in the parts and in the construction, combination and arrangement of parts as shall come within the purview of the appended claims.

I claim:

1. In a combined mufiler and oxidizer for the exhaust gases of internal combustion engines, an elongated, hollow body structure of substantially uniform transverse cross sectional dimension throughout its length and comprising substantially identical halves having meeting faces disposed in a medial longitudinally extending plane, means for detachably securing said halves together, an entrance port at one end of said body structure adapted to be connected to receive the exhaust gases of an engine, a discharge port at the opposite end of said body structure, a combustion chamber disposed immediately upstream of said discharge port; a plurality of partitions extending transversely of the interior of said body structure, means for conducting exhaust gases from said entrance port to said discharge port comprising a plurality of conduit means supported by said partitions in laterally spaced, parallel relation to each other; said conduit means extending longitudinally of said body structure and operating to transmit gases received at said entrance port to said combustion chamber, and means for adding heated air to the exhaust gases passing through one of said first-named conduit means and comprising other conduit means supported by portions of said body structure other than said partitions.

2. A combined muffler and oxidizer as claimed in claim 1 in which atleast one of said first-named conduit means comprises a tube having perforations in the wall thereof in at least the portion which extends between two adjacent ones of said partitions.

3. A combined mufller and oxidizer as claimed in claim lin which said securing means comprises bolts extending through wall portions of one of said halves and threadedly engaging threaded holes in the other of said halves.

4. In a combined muffler and oxidizer for the exhaust gases of internal combustion engines, an elongated, hollow, body structure of substantially rectangular transverse cross sectional configuration throughout its length and comprising substantially identical halves having meeting faces disposed in a medial, longitudinally extending plane, means for detachably securing said halves together, an entrance port at one end of said body structure disposed co-axally with respect to the longitudinally extending center line of said body structure and adapted to be connected to receive the exhaust gases of an engine, a discharge port at the opposite end of said body structure also disposed co-axially with respect to said longitudinally extending center line, a combustion chamber disposed immediately upstream of said discharge port, a plurality of transversely extending partitions dividing the interior of said body structure into a series of compartments, means for conducting exhaust gases from said entrance port to said discharge port comprising a plurality of conduit means supported by said partitions and extending longitudinally of said body structure operating to transmit received exhaust gases to said combustion chamber and including a first conduit means disposed co-axially with respect to said center line and a pair of conduits at opposite sides of said first conduit means and disposed with the axial lines thereof in said medial plane, and means for adding heated air to the exhaust gases passing through said one of said first-named conduit means disposed on said center line and comprising a plurality of conduits supported by portions of said body structure other than said partitions.

5. A combined muflier and oxidizer as claimed in claim 4 in which the meeting faces of said partitions include opposed semi-circular clearances which combine to form circular seats for holding said first-named conduit means.

6. A combined mufiler and oxidizer as claimed in claim 4 in which the discharge end of said conduit means disposed in said center line of said body structure includes a screen covering the discharge end thereof operating to confine combustion to the downstream side thereof.

7. A combined mufiler and oxidizer as claimed in claim 4 in which said halves comprising said body structure are formed from castings and in which the meeting edges of the side walls thereof contain opposed grooves extending from the discharge end of the body structure to points terminating within said body structure adjacent the gas receiving end thereof, and in which said other conduit means comprise a pair of tubes mounted one each in each of said pair of opposed grooves and extending from an air entrant end at the exterior of said body structure adjacent the discharge port thereof, thence along said grooves and thence terminating within said one of said first-named conduit means disposed in the center line of said body structure with the air discharged ends thereof open in the direction of movement of gas through said conduit means.

References Cited in the file of this patent UNITED STATES PATENTS 1,877,523 Gordon Sept. 13, 1932 1,985,713 Bartlett Dec. 25, 1934 2,020,054 Ford Nov. 5, 1935 2,038,567 Ittner Apr. 28, 1936 20 2,806,346 Clayton Sept. 17, 1957 FOREIGN PATENTS 270,541 Great Britain May 12, 1927 954,283 France June 6, 1949 

